Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ef2c1bc7492fe470e3e3a8d60a299a5edf61dc1f13e6deb8276003a783012d55' 
  AND token = 'jJ6pQ+I3DZgJgncC02kGTAUuAZsqJfNqIhsO2fKGsVc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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