SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ede438f6fb483b2b59d7d0970b3d3d518acf714d39993e0c3e7810cc56869502' 
  AND token = 'J0HU9MGAzscl8LHXmlBJ/nVsU0APiC9cUWSD0uJ8V68=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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