SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3dda2ceb9a360ce35de6382e301a5b20536b4f232bf05b65fc2a4f7f57fbba41' 
  AND token = 'FPCZrB28VrWr+x4LO8GOfe/2MgR6xUAofWMzLxXKpvk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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