SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '17ac1f97a3baf991d978e3f2adac2ab852569bffef550bbded192ebd28da4683' 
  AND token = 'IIickhQSdUUrBkrETpXe0MClWosghfPUfd4LCsTtscA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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