SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6ae11709a82a3bd204bab8585d5218db73ae3733f421d27653a06474c529d76d' 
  AND token = 'odYoS7zCaiV13lWo2oRV0/uYkMLXp/XwbiU3oS1oW4A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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