SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ed34e5f2c08be0adb509611423f58edca2c592c57534755091d8aa3229a74151' 
  AND token = 'XF00VvYnNsIQOB+SRvPaulGjN/ZY3DM6GLK0y8tuM+Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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