SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '771b85eb0ba9e818c5662e67bef8c90654cd633b8594a69af23881419223c97c' 
  AND token = 'cjcAUeY7mmYs5EtjJHVRkD+q28I+xoa7iw3+AIlsCsc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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