SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5913c58f1927f373939983b58fd32bfe5da2b3b25d9d278480544f1e28a3e463' 
  AND token = 'eVbZKi5ltLEhdWg4ZRqadD/UJT17qteF1w3bXzpN3+8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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