SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '0a7c0812f515a666c0dff56b9cc0ddc0176c8fb5797afe18147e175d59390e48' 
  AND token = 'IVeaVaNpOhfpFxCszCUk0CtoODZfJUZ3FpCv2XYSMLk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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