SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '758296d855a0901209f38e4b17458b1fd768a8b9a5d9de222ff9b8c46d068ce9' 
  AND token = 'HytaxwzFZJXdrVh6Phs+UlFaHvgm26kYnwXDSdwWHcQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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