SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c75ef13890e84939db8a70b44d77cbfde53dc97f818f53975a93d719b581150f' 
  AND token = 'wRPt1ippsXHk4v27YtR4UxNVDx1OMtmchQP43LUSykY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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