SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd170cf9acc76abcc84f2140a7991837fd505b401dfc8936154ab00ea8ee0c35b' 
  AND token = 'Oql/vT0ewHqJtjX3rVPe7ASTyRc65dIXlcK2hndKTpM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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