Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e3bbf9746d799c1dc9aa9a3fde75684c43209d7eb435dd8db8dc53538292b250' 
  AND token = 'uNOg2NdencdyV4GmjCcWPFrAcn8BPZEBzJmcvlOB6v0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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