SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0289ca118fb6a1c25175a3ef16ab2694915ddec96f2f22af1e067290fd774d85' 
  AND token = '2aXYd/gAyOkE6mrpkrFAV10dKHHuKobfCQV5oWG9cRQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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