SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5a317380d2d4aa30c2af34664127688df5c5d00adabaca9abcd2dfde6bfe7269' 
  AND token = 'HJFQhbC3qZa0d1eDQQbdKTczWBG4xW56OdShoUMYkTA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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