SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '62c5579e02f35c4bef590efef650f6edb353a575a78f9757405693f98651a783' 
  AND token = 'meo17eR21CLfPTing91Il2i3NOyWDVLZ7lpnX+JMdCw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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