SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3dcc770f2871cd37e8f70a4d03d2df37bd5327744e01f979627824d278ae4307' 
  AND token = 'z4ZpO6SJ1MFFgNR8vhkBZu1EMBw/KhLxS/YdVlwXUXE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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