SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd369b44e285184f04799d37b9cb9b78448835b8f0d7cb460de44784fda6a2364' 
  AND token = 'HiEkJZ7Hffwvexrcfv3NEYvhYmHORTu/sPTf24zqRQM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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