SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e4b4f6801426fe53a1d5ca0199ad43873f210f6bb04938ea978f1cdb82e81bb7' 
  AND token = 'lpYOd+vHhlV9pjvQHCFb4OPeG0ttTMeBXu9V/Sm0heE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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