SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f08c77fba370a558869c2a8e1d3b0050b50ab2b07b28d660e040acea523839c3' 
  AND token = 'l8kTxLzh7gqT5PUoRuqV799hiXpmWwQQHV+JZ20fZSo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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