SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c0f5d6fe541aea74f09f954c84b13fdee7fe95ac208cd6aadea97ef8ff04ee7e' 
  AND token = 'c6d4xngsqCgFaBGdqlgiO4EhiE0S4nHKfaQfkC8+1H8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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