SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '10e727568ec7950961a879845ddc27ff6b433c072a71cd40266e38e39cd06470' 
  AND token = 'jiC5xMQrCBYzhftuoNe3MgS+qlX+UBAjh7MDTrb3nhs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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