SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a1aedb823d58d90cbf16e9f00068df3272bc02bc83f922578b55dfa1beced7bc' 
  AND token = 'Gw9TjCHiQ9Ipy1n/jZPoGsv/Gw64XwxS9A/+unxBV8U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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