SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e06401d1cfccd0a36ab18e568ca6cabce38e730c67e76ae9205d1eb05f4ee422' 
  AND token = 'LhsfRd012G5F4PzVHMs7cjQDfQvFVPQsD+1BvIesXC8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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