SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3f021880f78ad4494e99b72bb544c51820312c1e83afe23189766c05f9f4bc60' 
  AND token = 'uXsQNWTbHiKTWuMilgTS5YNqyuYtpPSSMAAX1y6PVMw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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