SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '41c3b0db801a056b813787fe8f3cc81a39f19f7d182b84ebf01b610a36132cf1' 
  AND token = 'nsN7bVsTJDlR+Pfm3yUCQHVGICx4y38k1+waGYPM7Ro=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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