SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2f9759b1faafe5eee88a95b68103c7744a29013f0bb133b578c4b5306ce4ff3a' 
  AND token = 'IKr0RdCoXBwcZn9+sJLRHOXgjXjjB7L7x7AcVWCiWbI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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