SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2563f608d136cc21922ea65080a42ac6e6fb201f98c95c728130aeea9caddeaf' 
  AND token = 'sWLpzWJO2GEAxyky/LqCnZiKuQGhMMshnqWCHO/uNvw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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