SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cd706d6d907551c60096ab73db03fbb06a0a4a2ccdc0f4ccc1696693dfcaa403' 
  AND token = 'rZPexvYN+y2VkgOdkOuJGeaLLA1R5og1UuSXLzTiSAA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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