SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2c02bf67c56382b781cd5b972858313e933ba01ae833d5b0ec629b403252d74f' 
  AND token = '3GqJCkNo7Ml82Lx5AQvA10Cb8uhTO1jdXszVZR9PwRc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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