SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7e5db41447b96c1ab3094663d54c167ceef2ae87a0e8c1e45f54b4256a5fbc8d' 
  AND token = 'JeuMSgIBmND0HF3XxGlCLwvfGzSbnXUvQulwKBxr+vs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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