SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dff6545d723b14f82d0174b3852a0568d88f58b1ca00242a58f28011132f9334' 
  AND token = 'Heuvgzzl+XFdLZNFbTQKh6YRwj/s4bIoY9VWt49v3VM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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