SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '69633ac0a7eb9789c06eb9d20239870cd42fddb7b2e80c58665113c2f9b12530' 
  AND token = '8GGJNvxoH6fgf+NFu15OXMr/JZZ4OJMdJPzvwwjV0kM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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