SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0f969da4935541e66b94c691198a21097ffd2ffeb960b061e300732f96dc5fff' 
  AND token = 'VAbqF0tna36XpK4TRf7eVi6KiWjA9ONK+K+uM+z5iYE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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