SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd2b4bf8e5a8cf067de9b2606f2ff59dccefc6881eefe45e674dc974e12b2d72f' 
  AND token = '1hgSQ/S90VHlRPzNuZ+Ypl3G8pdwK4IfLMizncm0FPY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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