SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7909aa9c470a869df372ea52c16dca9e8c8fd67fbbb0f6007f64e1121238c1bb' 
  AND token = 'Rju+BQZv6FxV4NIo1eRmaBO8mYioo+gqIVgeepuSJQs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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