SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '59d26fa40bb233a0f8ec4444e6ead907f4edd32f28a27772dca45c75d68d1551' 
  AND token = 'Lyn2IPPo0pMFa2K/gaA5dTUXIueUuXN99BIgkTKDjpc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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