SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4c13536d9f2d96d6479ff5abd6ebe05c21779b1a84ac7f6d83431ea77acba839' 
  AND token = 'RzJI0Kpj9XLsd1G2MDp4Yy+q2szPrq4fhyiJ4IcxxgA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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