SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ca79665d43010a038df708e5585aa26554884d97f679c036852d8bef126ef66b' 
  AND token = 'DcxVhcgWxBPR5zk6FFinp5j5LMDdk6yzkj/WHuG2ZJI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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