SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0644ae150a706aa1375f5645e767cde5bf71a01ef6ba760e93c282374b2a6318' 
  AND token = 'HHv//BAD9lTS/oaeyfZOZUfv4Vvg7ZeTeplr9oaqL+Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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