SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a7510ae563c97265123d20a187faef7ae1c74d0038b3d6e073d6b9e222cba255' 
  AND token = 'BMRlJuRmhHJqItuqF7TpWA57DhjnGzVpiqPZsTTgPms=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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