SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '18b1acf13d3098645f9b88f5242f931ce27dcfe72531c6f37caa76dd964a5ed1' 
  AND token = 'Dq8kMMNnNqC/ukKVovzEKMtzwmzFC8CBxcGQx2om/1c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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