SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e52aa26c5e7839396db4fa36f18b4ecf7fb8a754902206a9bb57db711a4f86dc' 
  AND token = 'DfJryB/GxlWfHGJI7lHCRWXSma/wi5ZIcRhkKJQPYRk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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