SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e18103e2473ec992c8fc87dfaf6dc9bc3f7fe439408b6068cb5cebc69b459c6a' 
  AND token = '/1lKoR6gDwau34NF2PvipzIoOxRo2iHRG186JZ72dKY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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