SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce05eb98700d1d5302fb7d2692fe391bf937b8d8b6d1ce2ef6863d1e10cb0bba' 
  AND token = 'D2WQlYk+oTzdiyd2hYJfAdWJSveqZR5+3ldkd9AfGoA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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