SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bfc3fc8267a71c345740bf31fc3150827d1187c12d5f617038a434da0f4afa2d' 
  AND token = 'zqD38hbf4v1gREAjlJCV/G38FzGDr9G+vbDJQQwuoyA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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