SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8ec57e4db9d5f0acf1981c7b17634a730ea474592a2bddabd1db83b8e06b8c94' 
  AND token = 'PdbI59cpfDPBhmf2Ju/AIcNgCpeRn+jxZAcYTUelTtw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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