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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f8df44aa54a0ea70a2e06b358b86b54630962b0a4c7f4fa4c7a34599d7864bf1' 
  AND token = 'yJ1UNW01LBQ2uhZOYX1OKuuaNcVsB+Vs182IGOQZxRE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}