SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7e2aa666749ca761d0c272291ca55c120150fc1352eea3d7ac682b5855a10835' 
  AND token = 'XkTBLGZ3b18P1jxWVwoCcJ7L9LkgyVFSA8zhfFErJdg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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