SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f8ebf31f9a5332050b3a915778ca542c8ac10a828b238677889c112c5bac5ee2' 
  AND token = 'VhsrkbJ0KYsLTF9g4zdlebE7XE8KunZ1FWaqOfYPbuY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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