SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ffde7c99cfd91e463ca361cdc53167a4ee811974a8ed23793031a454cb708edc' 
  AND token = '298RQ6wD1QNI7fANcTUTTS4FGyNwbppf+lvuZhAYjHA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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