SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0517ff80b634f542a4c739eb58059b1506c8e029acf8d4886dbe2649a3339993' 
  AND token = 'nAPA47nIPnT7dvLMHwkkV3PtzAuYKoiJ40wcFEFhepI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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