SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1a2a1660fad42ef93b6712412e80efb3483f1f87b7c0ed42def87d7947068ff7' 
  AND token = 'OVRHYF5E43rJ0Olk7/jUWQK8sKJDBm+u/Y7OAK9QPdA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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