SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '93c18e23feb503f885ada63c9b1f8d8463dfe373ac48c539af7c5db7717462ff' 
  AND token = 'cPXO2H8hJSPTBW4UzKZPxkL6E9Yjil0AuNhzq1yD3lU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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