SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '24f4128be1bcaebc4ebef6c81cbef2de4f760f76af489fad256bd72909afe15a' 
  AND token = 'Jz7CkmXiJmYNoToDg9bFVqM5L6bpkZSUlBUXBkMZv1c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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