SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '60971a45532b415531e8890b03254c38af7988390c2277d329e42cb71840a354' 
  AND token = 'ZLp/6KfqY3fqH4Zmhxhlk8LaBgQgXe+qrbXXbE8gGDg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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