SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3bae2172d9a8eac252b64e039af6c0e66e0e334f0d2de15957a06d6ec9f1389a' 
  AND token = 'BPFjB/zc5uBumEGQ/PPZSm2b7gEaSiAPIHJYVwbYllg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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