SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '46908bf9d9ba722329ae1531cb9c2547280e85bfe021c9705db280544d9a19ef' 
  AND token = 'GjQ5IzTy7+QCL3luPKO6P6UVsvC88CHBedxc7ri6wRI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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