SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '719040261250801c4fd2152f32ba30ab9d815b2fc345307f5ce8c075665c1289' 
  AND token = 'PnVlcmuMTIsNpcGw6oW7O80uzSQuFIkaDbRAFKzAEcE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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