SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '41692c89f52254b52b1cdd0e544734139bebb14b4f0dc991ada7f782a1db842c' 
  AND token = 'rtTp0Ftqreozs9WcJCcdlcfOZMIkqddW9hOE90jyb/I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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