SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e4c77ce80db7f463aec2412a07999c87c21f784233d4293521f4bcc61557b3ab' 
  AND token = 'OnO8uFZC1gqy0R+TMqiC8VFW25X/qY9K5EPD6xWtDJg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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