SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '86013896813462d66688e581ae085974ca5e5d68ec215d8578d53cca60e8e373' 
  AND token = 'BUDUoOKc7BRcnmr1FdWvVFqHCHHzNw9GjrBGjPZJs34=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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