SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '004f30903a4884b83decc04e39ac16e7d66cfd0828234597068bd0fa6ceaa261' 
  AND token = 'pwLTkBT5CzHfiPGLAj/puIHea8VOE8Jev1lBf+celaU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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