SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '410dd582b71bd9556e6f3ffa9fcaf7ae6173c819872579f11acd6c9d0a14b8bd' 
  AND token = 'DWb/63U3Rnjk0qv4HBzj3ZLmXsYsfvla1HMPLw3qhHM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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