SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '20a1302ac61518a24229a8541abbe825e2be19fd2f2f0960c2851d6984adf5d3' 
  AND token = 'u/mF2MdeFGBxvebZJCFFSmwoqYFf8eEu3IoE2qpwIoU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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