SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5ec24e04b6573d893f9978dce3400606ecd12c935f92d1f63de75b9673bb6723' 
  AND token = 'q7xrfE06pxp6gjA10ghtrS4yP1ACd2ZYiyNgaAqpXx4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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