SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1b74ee02b2a5f9dbb7d8675c7db8500ee8443b8454187d7e2af5e826fe85bf06' 
  AND token = '5MN+5H+vwvKvE9wSAYUktinFH5ijL2vikwUVEfcOhWc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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