SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'abfcc12c3aca2f727f427af8e65e6ec5baccd4142bed4a620a6f8650d76c0e19' 
  AND token = 'HxYYwNOZ3CeAHK12ShhZLkXKsG4tki0BI3AVZ1mRMuA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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