SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4089a2973ea1202e58258217776536b63f4b38df0d4632bffb042130f1894737' 
  AND token = '5F0Vx4cca8DgOiJnBbUUwHb/AnNUWlCsK2VM0kKIL6I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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