SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'de3bd2bfce8370c3da7ad42ac1456df5233884c0feff2c5cf4b8a3d242372a76' 
  AND token = '1vKurI2HC7gkT9KihNZaqmwNTisoP49LjILxr4UIDUw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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