SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '331bfa0a323461d33261875f6a84fa43f885b74d2d4285c1555b7e92ad7f17c7' 
  AND token = 'UrkzwZxxt1tbU6QHy/7R7o/DT2YDFlom1AiZc8FBuDQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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