SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4eb7bac9668259efb8bded94b01b47bd21aa39e100c16dfec69bb7eaa1dbe74c' 
  AND token = '6QMh5l0Cgpku61OGWQNjUCPKUO4afJuSd6m40GWASkY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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