SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e58aec314abfe432c0c10bcc8ec2fe2d5072b505f586c3ddad134ae9bc218c85' 
  AND token = '9BLES0XEAjxJIDmFrQVxFHxJiKqZOybdQYP3DqlHcEY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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