SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '45215143f18598be79e7156d1c308c3309dc74e89135e6af80671c7eedbfe4b6' 
  AND token = '6K97SGAi89dnqWRI1ZDrnT8YTijZHrFk7694rTtGQ8Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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