SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9b2e3f3bedac8f7acda043f0a7b3f2f00a910078cb82d6148e996e85b965181d' 
  AND token = 'JdZJpPA0r1sDNscqAbO2rT9iHMa1e5kvxJOcgwHEySE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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