SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bbcb566616f02c1cc9f544faa7be10dcfbe8e75e42cb786a1f25cf20736a0348' 
  AND token = 'hEGIjbRJUJP6QgR9G/NZY6jmHLtTh2+Qxbzzanuw1SM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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