SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '02985ca970c49670053137e2d1c154bca0bb6063fedf888b97ce83c738a1f919' 
  AND token = 'BdXABwvGoczm3nbmvIqkJTkC4s6MSQtEKx29WZWJkHI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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