SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'df1d38adde54c31ca80ebc19f5da7dfe38a46b35308e43b1f719cdd4cb14e222' 
  AND token = 'Ss+mr1H19JRQ92Kei0ge5d39lHbUVZIQwyeQEAUGyCA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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