SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd349fe5512b74a79211e8fe3026dbc5cecf033713c426b0222d089cd4b84d78c' 
  AND token = '7p2sIRmJY7fFayHtuAcMFCz88AAxFlrye/6F/m83O3U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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