SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '164c3f602a0b653d27b19a50466da055cc30ec88653492a9316a2b8165332718' 
  AND token = '8FDVY+9V+aQ7fhONYqmSOtJjB+XvC+PvlZxg0GtUkPs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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