SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '24b65841e356c1eba311b3234f8a16ba414f818db761053055c18cf463c7484f' 
  AND token = 'BbZxj4dGUMFeuKWXovL552/9amOBfhTgLeZOiQg2zmg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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