SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '774932061db252b74919d78e962337c00f9235b8143a22cf99f5f775a3de67ab' 
  AND token = 'jPg+o0mTzqyg2zP3lU5aFQvtLdWCKM5hCGkKqPdVHXk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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