SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'be75ea1f3389c869d15b1ea75d4e18890c79b7deecc9fb31550bf6d247b5f91d' 
  AND token = '+9ZWD8+mHGbBGBAZjO9ZxpP54IohRR7Vmffz+MBzuYg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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