SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd08fb20d76709819b45329cb42a106e0ed21b5a6b30daa74beb7d5df8ec66098' 
  AND token = 'rbx97z0TUf3xNx+YQ8w6W5Ueel7MPhgnCGd5AUJf2Sk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}