SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '890cf5e0fce2f253007aec4feae7bae67865e7083245428868cbe31dbc827335' 
  AND token = 'dBeaJVurdNlRRB2wGesd+/dV//NfcccMTcKKClmN/PE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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