SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b6ed7994c49e20f8274acf7822994fc10210a8b555f80582168a7c9fa66f5616' 
  AND token = 'rUwK7pzVGtNclZIWkwmp7gXbujrcIYvMB4XJ3uW1Rtc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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