SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '200b86619764afc5dbb38f1b6f3a71ea9372967ff512f9b181158812524fe867' 
  AND token = 'AG81VrdbMwqPb7h/mIL5woA7dlDlf8toMoPcakfH5dY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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