SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a87c023efc034ea02b18c6bc5d0cd5562e4b4a19ab191ff84663535de1248998' 
  AND token = 'bMiXSGSES42ifakIW0n1esB+jZDVdBKOxjGOiO+Fzjs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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