SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '66af0963e939be701755d3b81648db3cac03acf862569ff7d7cd5082fde93cae' 
  AND token = 'bPEguGDu4jGYJQOb+/v0AlElEFpiv/VhrbAiAwUxfyU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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