SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bafd57962771199020df9e62d72603ee7a22915d1b03c42234c5c9710a91b5f2' 
  AND token = '6A2FCCRSkZSQNquUYHFzn6EJALu6tWsTnuBCKs9qxKE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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