SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c41b50fdec85ef55372fbc7182370bd41cbbf19d3519ca6cd71a4f87f0b9d2ba' 
  AND token = '9kZYBPnOvRka310XsD7Oaa8QAmdtVWITVfOIcKAUnHs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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