SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1b9fb991a2947e6ce9ad907ca992f1dab467f9b702eda234cc1c145cf6e7d2bd' 
  AND token = 'xk8yEowUn15HZecDNLuKecfYVzJUS3vGuyRxXL8Q3Kw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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