SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '609732d71489b024a219ebcf00ffaca9a895a14dd0ea91aa0f78b621fd7c1a13' 
  AND token = 'gq0lp+/T5Do0g7VMMbIFkQ3RucEKNzAjSHQmtg6Ziu0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00061

JSON explain

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