SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8756e09c1ae46bd0ccf4b30703836b1308f179b52e6f0471e84019b2c29d27b8' 
  AND token = 'h5pX6pCmyMNctf5aMT/0Kx+2KqbZggnvglqSVljXn4k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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