SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3becb472d3c84355378f44ff8d359c887f271c2818560479c37a3e5e638f87f6' 
  AND token = 'LFPE911+BZXsR+BjSmKLPJFAHRymn4bR/hqIQUDs9eo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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