SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '15e6a6450423dfe24263d6e85b03226f6f812fcec2b233ee73d164b4ff9e0af8' 
  AND token = 'sbBWQahtGaralXzZpmkwjXjhOyFS4BEsLQCa/mns6Bg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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