SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '48d439d05680546f6210001c0123cab309ceda9a1943e51edb687eb219d8d495' 
  AND token = 'eE5MvY0arsizWll9RN70lRXCVww+8gKeDsZ/QZ0xxNQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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