SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e0836c81f46e08f900722bd30fa258146b94046ef510a2c0fb9009ae1a72ad60' 
  AND token = 'Ybehwdx6tr+aK7txTbwGnp0oGagVTE5Mfvh0Azujgxk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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