SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bfd74d2b02fbcfcbfaa48d96f27441b47bce0dbc450e1efa0e9503e11f0c14c6' 
  AND token = 'qXfqu45kBqBi0NRcARrL+oRcySwXrJRkNDgdcMogZo8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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