SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '82375a3cfef1e732531533bc58e2998294c5902533c005d0011d19cbebb59821' 
  AND token = 'K7EI3vegm01/eHZLzztiHCRpTEMcGEMqCnnVrvncLNQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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