SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f80d5c7844ff3981c53519cfa54dc2ce6e67a12f0a694f1787e28f3cb43134a4' 
  AND token = 'xu1oj6TJThEQE4fsa+AatKpVYO+HKZlrA665zPzvOZQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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