SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f13226d44f37cd0ea9572297d53d7939d60c7daa149eae2ea8d516c60feefa07' 
  AND token = 'd8VRn6uiRFgOvNyhqnTIBX8uznoDmv+ovP4qUN6sgEY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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