SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b030c3cf1c7da0bc16cbc9a03ab1d09ea16e6531776a8548d77b00ace94f4ebf' 
  AND token = '6deJVdv7qmJc0WKL62dLrSH8bvpkZbYGVqiFG2mVAsE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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