SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2f909fdc1f3c8289edcee10c7df0feb49fc97a5f26c8619516bb0f91b4f97e2a' 
  AND token = 'hsdHd408SQD3jQNedsZw5pGjLcFF+bxikqCXL5WILCo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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