SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '970428094d225ab73c12f52909f5141ed25eb7dbfd6eaa4da3a7685925c6d7bf' 
  AND token = 'H4ZMTgviInBUnaYX1VU3EiUpVRagwgk9Kj/0KMPPA9E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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