SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a54e113690515da51170c0c9a7bd074810775b1f072303348a0584e56d5005c9' 
  AND token = 'ZJheYtjqXiy3rFLIUwFbEqB4/aUMsXRX5fzMGToNrt0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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