SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '7d92e8cad6391b65cb1de24b5956cdd8758e0e15f07e0d420a3cc787c241c3bc' 
  AND token = 'Bq7HvWiF2l+WNDXRnjc4M3rAzT2fTSAsZTQFTEubit0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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