SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '38ba3effb5b86da32fbb30ba8305f0667c32a41bd0b8c5fbbfa38cbafccceab1' 
  AND token = 'fdDE+quGa4pOniEFYTsICPMOSP0NdOQJdw1HVWsQyRg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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