SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c0be349838176e3ced2b81b49327ac05ff222110f4318dbe59a991889a5833cb' 
  AND token = 'sr9FSxGtaAN3zYpbrV8oBo1m3jid/L7JVHNQbD2MPtA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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