SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6f6d8d15e3cfb6e042526cfb996e3c9243ef7aadb2d73c0fc837026c42050908' 
  AND token = 'PIh/Gc+P6lD/7pxXKGGF4FqLhl/uUhHaVTeyPTRNQ4M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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