SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '653bb7adfc397bef26cd0fb3fffca26e02988f908a8c44113c3d927eefe99d3f' 
  AND token = '6ecICZhcLDeGS905PmuuZzd3kjJFVC4QCsmwzG1uVVo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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