SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7c0e20eee8eaa535e4cb6ba78c21e2086b4ca573fa48c3038c2275b9cc25d2d1' 
  AND token = 'uSIPRifTHcaXazi8tJJFMXe0/pp9bdwaJTzeF8+LWPk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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