SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6e83856b4d7a60af0f32c6ca270b29b22f97384cacdf8f5453ab98dc172c6052' 
  AND token = 'Oy18w8/XQ5yvrLJsk9WjXeh0zGrZEY3xgm3/HAPqpgM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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