SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '84625fca6c7c1d82551d7f229b0e667bb35465da5e3cde6ea622eb9a02fd3c98' 
  AND token = 'XOWIhDE7QorZidCGKlmxiESyrSshr2dkEZwXEZBDqHY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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