Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e20c3816ae614e6f7c5de7e323bd9ce4e1e29714da2287e2115fda9187262b42' 
  AND token = 'uvff8jIjAbbs3oqoMtUXqOLFEIRUPzenm4AhDmnnxQM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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