SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd6bdfd52570e900bd4f0602e6cc05c80fc4b1029f2e40e5381887ad2dd0378fa' 
  AND token = '9cvkj57aFEegEGBAXiDscRasXBvbo+t3m/GPukLGD94=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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