SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '13ed8743e7c622cd3fc6fd051d4037b421c4bd4ff1359ccc49717a79ca950ba8' 
  AND token = 'jGHbZAk2y1uplAuGRHASYZoGTHsJzNeMPkIsMBp4nWg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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