SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '21864314b962d48eabed95040515548c2b99d88b46d6ddcf7e5fe19ab567251f' 
  AND token = 'Jby8Pk+u8IXzcmVPOFp/P0D1doyOQ/IjAO84f1A7C7s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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