SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cdbea111a9beec08689dab8f23805a6bdbbec6208c1d6cba1b2628605bcbd6a6' 
  AND token = 'xjGZrUhdKcqkDNcaPIn3vxVjBQ+Cn2eYyb7Wumh9uH0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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