SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3fc60271291f3b4f5979147c05ac9dc513f50f050aaadcd28bfe32164161c9f3' 
  AND token = 'jVYRc4pUlx5St2zzGpI33nm76Jpeqp+ujZA4kQOGggw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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