SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '323136f47a551667de4f5ed14de3c4255de44945e20227238114e0f28bdf9fe8' 
  AND token = 'jY2aDCvS3ZhgiVmutCDiQ1xFCGjYXZdz/iVKcstyRuA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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