SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5b419bfb6cf0f7bbc11cd7ce09867687e5326b31eec80db2d389fefc22e2aab9' 
  AND token = '9UPm6KQXydWoleEYZgyqimhuRYbUG5bTitO2dRYhreA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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