SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8435222826bd9d73538e85708db4292abe017b3d3f4daf32ed74a9a237bae15e' 
  AND token = 'EPWeOXbmqj4WL7ftxgrPAndnqB5QW3zF3iO1Ro3dlkI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00055

JSON explain

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