SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '90d1455f1eedc19e685581c8a14c3f5e2fcd328ba04f681f342467fa66b009df' 
  AND token = 'wH3wCau/OzC5Xjc/i2rBaqhoqOkVc7k6CavU8d+WVIo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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