SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'abff61a12aeeed9cfdbff450275c2c3889c4926759897aa5e9471086194028c5' 
  AND token = 'VWV2Q7vDP2mAm4PvUSwAfkGShGRQohcRwxY3kY0F9XA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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