SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ae2664b014b44342c859824ace09302705b8eea12055facc0776a372e36deb4f' 
  AND token = 'lB/E0Hq4Ko+aHi0wJ9C/FVYvG3mXtj65xC89/GxtlgQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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